Today, let us dare to make a mistake. The
University of Houston's College of Engineering
presents this series about the machines that make
our civilization run, and the people whose
ingenuity created them.

My favorite among Josquin
Desprez's motets is an odd piece, Tu Pauperum
Refugium -- Thou art the Refuge of the Poor.
It begins with soul-settling chords. Then it moves
off into the complex polyphony Josquin so perfected
500 years ago.

The text recites the attributes of God --
"alleviator of weakness, hope of the exiled." But
when Josquin reaches the line, "path for the
erring," a strange thing happens. The grand order
of the music seems to break down. The countertenor
line stumbles about like a man lost in the woods.
Where is it going?

Josquin had the mind of a linguist. His music is
rich in word games and subtle text settings. What
he does here is to teach us all a lesson about the
word error.

It's from the same root as errant,
which means embarked on a searching journey. Five
hundred years ago, the two meanings were closer
together. A person in error was a person searching
for the truth. So Josquin's errant countertenors
search for order.

Lewis Thomas picks up on that theme as he looks at
DNA molecules. Surely DNA is nature's most
wonderful invention. It's been the formative
element of all life on Earth. DNA replicates us
today just as it did when we were no more than
primordial slime.

DNA is a marvel in the way it flawlessly replicates
any living species -- well, almost flawlessly. For
the DNA molecule does err. Every now and then it
makes errors and provides mutations that change
living species.

Thomas points out that if humans had designed DNA,
they'd have found a way to get rid of that design
flaw. And if they had, we'd still be no more than
anaerobic bacteria. There never would've been a
Josquin.

So DNA makes its errors -- living species do
change. And I find a line of Chaucer, written a
generation before Josquin's birth. In it, Troylus
cries, "O weary ghost, that errest to and fro."
Troylus tells the painful wandering of his own
spirit since he lost Cressida. In this sense,
erring is far more than simple blundering. It is
searching for answers.

That's what Josquin was telling us about human
error. It is the path of our search. That's how DNA
works. Through repeated error it searches out new
life forms.

Today we begin to see that's the core of the
creative process. Engineering design teams are
learning to make errors rapidly and correct them.
To create is to wander off the path, to be errant,
to start in one place so we might, in the end, find
another place we never dreamed was even there.

I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.

(Theme music)

Thomas, L., The Medusa and the Snail: More
Notes of a Biology Watcher. New York: Bantam
Books, 1980.

Thou art the refuge of the poor,
alleviator of weakness,
hope of the exiled,
strength of the heavy laden,
path for the erring,
truth and life.
And now, Lord Redeemer,
I take refuge in Thee alone;
I worship Thee, the true God.
in Thee I hope,
in Thee I trust,
My salvation, Jesus Christ,
uphold me,
that my soul may never sleep in death.